Songbirds adjust their travelling direction aloft

Departure directions of migratory passerines leaving stopover sites are often assumed to reflect the birds’ intended travel direction. In a new study Sissel Sjöberg and Cecilia Nilsson show that birds adjust their direction also after departure.

Photo: Björn Malmhagen

Published on Jun, 22, 2015

By comparing data from automated radiotelemetry and radar in Falsterbo, Sweden, they show that the spread of directions increase with altitude and that the departure directions measured by radiotelemetry have the largest spread of categories. There was also a surprisingly large spread of departure directions among birds which passed a known reference point a few hours after leaving Falsterbo.